KR102038377B1 - Electrical connection tape - Google Patents

Abstract

The electrical connection tape for thermal management comprises a carrier film and a composition comprising solder powder and applied to the carrier film. The said composition contains the soldering solvent in which solder powder is arrange | positioned inside. The composition contains about 50% to about 70% by weight soldering solvent. The composition further contains about 30% to about 50% solder powder by weight. A method of making an electrical connection tape for thermal management includes providing a composition comprising a soldering solvent and at least one of epoxy and / or acrylic, adding solder powder to the composition, casting the composition onto a carrier film, Drying the carrier film in a drying furnace to form a dried tape, and cutting the dried tape to a desired width to form an electrical connection tape for thermal management.

Description

Electrical connection tape

Cross Reference to Related Application

This application is filed on Feb. 11, 2015 and is entitled 35 U.S.C. of US patent application Ser. No. 62 / 114,820, entitled "Electrical Connection Tape." Claims under § 119 (e), the entirety of which are incorporated herein by reference.

Technical Field

The present invention relates to materials for joining electrical or mechanical components, in particular materials for attaching electronic components and related devices to electronic substrates.

As electronic devices develop further, the ability to quickly connect increasingly fine pitch metalized features during combinations of substrates becomes increasingly difficult. Traditionally, depending on the substrate type, such connections are screen printed with solder paste or anisotropic conductive paste (ACP), or coated with an anisotropic conductive film (ACF), or It was produced using preforms, wave soldering, wire bonding or solder wires. However, each of these methods has its drawbacks. Screen printing techniques are pitch limited and are not applicable to many applications such as flex attachment. ACF is significantly pressure dependent, provides only low current carrying capacity connections, degrades over time, and is expensive to manufacture. The preforms must be placed in or around the solder deposits to keep the solder deposits in place during processing. Wave soldering requires a large amount of energy and cannot be applied to many attachment applications. Wire bonding is a relatively slow and expensive process and has high reliability issues in many applications. Finally, solder wires are also a slow process, which easily causes flux or solder to stick out to unnecessary areas of the substrate.

One aspect of the invention is a carrier film; And a thermally conductive electrical connection tape comprising a solder powder and comprising a composition applied to the carrier film.

Aspects of the tape may include providing a soldering flux to the composition in which solder powder is disposed. The composition may contain about 50% to about 70% solder by weight. The composition may further contain about 30% to about 50% by weight solder powder. The composition may be patterned by epoxy and / or acrylic. The composition may comprise at least one of epoxy and acrylic. The composition may comprise a "suction cup" morphology. The composition may include fillers that increase reliability at high pressures. The filler may comprise a glass frit. The composition may further comprise additives for process temperature and residue evaluation. The additive may include at least one of Leuco, Leuco analogs and liquid crystal "thermochromic" dyes.

Another aspect of the invention relates to a method of making an electrical connection tape for thermal management. In one embodiment, the method comprises providing a composition comprising a braze solvent and at least one of an epoxy and / or an acrylic; Adding solder powder to the composition; Casting the composition onto a carrier film; Drying the carrier film in a drying furnace to form a dried tape; And cutting the dried tape to a desired width to form an electrical connection tape for thermal management.

Embodiments of the method may further comprise a composition having from about 10% to about 70% by weight solder powder. The composition may further comprise about 30% by weight to about 90% by weight soldering solvent. Drying the tape in a drying furnace may include drying the tape for 5 to 15 minutes at a temperature 10 to 15 ° C. lower than the boiling point of the solvent of the composition.

Another aspect of the invention is directed to a method of making an assembly comprising an electrical connection tape for thermal management. In one embodiment, the method comprises an elastic carrier film and a tape comprising a solder solvent and a solder powder and a composition applied to the carrier film, between two substrates containing metallization and to be connected. Laminating to; Heating the laminated tapes and substrates to a melting temperature of the solder powder; Melting the carrier film to which the composition is applied as the temperature rises; When bulk melting of the carrier film begins, the soldering solvent is deoxidized to act as a transfer mechanism for the solder powder; When the melting temperature is reached, the deoxidized solder solvent wets only the substrate metallization, and the floated solder powder is transferred to a desired metallization region by a liquid solvent; And cooling the tape.

Aspects of the method may further comprise laminating a tape between the two substrates for 1 to 10 seconds at a temperature of 90 to 187 ° C. and a pressure of 0.02 to 33 psi. Melting temperature of the said solder powder is 137-289 degreeC.

1 is a schematic diagram of a tape of one embodiment of the present invention.
2 is a schematic view of a tape of another embodiment of the present invention.
3 is a schematic diagram of a tape having a suction cup morphology of another aspect of the present invention.
4 is a schematic view of a tape of another embodiment of the present invention.
5 is a schematic view of a tape of another embodiment of the present invention.
6 is a schematic view of a tape of another embodiment of the present invention.
7 is a diagram illustrating the use of an electrical connection tape for thermal management.

The invention is not limited in its application to the details of construction and arrangement of components described in the following description or illustrated in the drawings. The invention is capable of aspects and may be practiced or carried out in various ways other than as illustrated herein.

The electrical connection tape for thermal management of aspects of the present invention is designed to take advantage of the affinity of the metal for other metals. The electrical connection tape for thermal management of the aspect of this invention contains the elastic film which apply | coated the film the solvent composition containing a soldering solvent and solder powder. The tape is laminated (or pressed in place) between the two substrates containing the metallization to be connected. In certain embodiments, the substrate may be made of any suitable metal, such as copper, silver, tin, gold, and the like. The thermal management electrical connecting tape, sometimes referred to as "TMECT", is heated according to the temperature profile, which reaches the melting temperature of the particular metal or alloy used in the substrate. In certain embodiments, temperature and time depend on the metal or alloy used, the film thickness, and the type of substrate. For example, the temperature applied may be 10-20 ° C. higher than the melting temperature of the metal or alloy and the duration may be 20-30 seconds. As the temperature rises, the tape with the elastic carrier film and the brazing solvent / solder powder composition melts. When bulk melting begins, the solvent deoxidizes and acts as a transfer mechanism for the solder. Upon reaching the melting temperature of the solder alloy, the deoxidized solder solvent wets the substrate metallization only, and the stranded solder is transferred to the desired metallization region by the liquid solvent. After the solder is transferred to metallization, the entire sample is cooled. The final product is two substrates that are electrically connected only to the metallization area and include fully electrically insulated connections.

In FIG. 1, the electrical connection tape for thermal management is generally denoted by reference numeral 100 and includes an elastic film 120 having a braze solvent composition 110 applied to the film. As shown, the solvent composition 110 includes a solder solvent and solder powder 140 embedded or embedded in the solder solvent. In some embodiments, film 120 may include a carrier film suitable for material application. The solvent composition 110 may include a solvent, a polymer, an active agent, a rosin or a resin, a corrosion inhibitor, or a combination of these components. In some embodiments, the solvent can be methyl cyclo hexane or ethanol. In some embodiments, the polymer may be Versamid® 940 or polyvinylpyrrolidone (PVP). In some embodiments, the activator can be a dicarboxylic acid such as adipic acid or can be dibromobutenediol or cyclohexylamine of iodobenzoic acid or HCl. In some embodiments, the resin can be, for example, Dymerex. In some embodiments, the corrosion inhibitor can be, for example, benzotriazole.

The solder powder 140 is compatible with the solder solvent of the solvent composition 110. In some embodiments, the solder powder 140 may comprise lead free solder. In some embodiments, the solder powder 140 may comprise a mixture of tin, silver and copper. For example, the solder powder 140 may comprise a SAC305 solder alloy. Solder powder 140 may include particles of any size compatible with the application. For example, the solder powder 140 may comprise a particle size of type 3 of 25 μm to 45 μm. Any suitable solder compatible with the solvent composition 110 may be provided.

Solvent composition 110 and solder powder 140 may be any mixture composition. The configuration may vary depending on the end use. In some embodiments, the solvent composition 110 may include about 10% to about 70% by weight solder powder 140 and about 30% to about 90% by weight soldering solvent. In another embodiment, the composition 110 may include about 30% to about 50% solder powder 140 and about 50% to about 70% solder by weight. For example, the solvent composition 110 may include a slurry containing about 40 wt% solder powder 140 and about 60 wt% solder solvent. The slurry can be cast on film 120, dried in a drying furnace and slit to the desired film width to produce a TMECT. For example, the drying temperature may take about 10 to 15 ° C. and about 5 to 15 minutes depending on the melting thickness of the boiling point of the solvent.

In FIG. 2, TMECT, generally designated 200, may also be patterned with epoxy and / or acrylic 250 interspersed in solvent composition 110. The patterned epoxy and / or acrylic TMECT 200 is designed to add strength and ability to increase the bond line of the substrate. Epoxy and / or acrylic TMECT 250 may also limit solder short circuit potential.

In FIG. 3, a TMECT, generally indicated at 300, can be processed to construct a “suction cup” morphology, indicated at 350, formed at the bottom of the tape. The suction cup morphology 350 can eliminate the conventional lamination step required for an anisotropic conductive film by allowing the tape 300 to be initially pressed and secured to its desired substrate without applying heat.

In FIG. 4, the TMECT, generally designated 400, may contain fillers such as glass frit 450 to make the process more reliable at higher pressures.

In FIG. 5, the TMECT, generally designated 500, may also contain additives 550 such as leuco, leuco analogues or liquid crystal “thermochromic” dyes for process temperature and residue evaluation.

Each of the tapes 100, 200, 300, 400, 500 of FIGS. 1-5 is in contrast to an anisotropic conductive paste (ACF), which is one example shown in FIG. 6. As shown, the tape denoted by 600 includes a carrier film 620 and a paste 610 (epoxy and / or acrylic) applied to the film. In one embodiment, the paste 610 includes conductive particles 630 embedded in the paste. Conventional ACFs include polymers plated with conductive particles, such as Ni / Au layers, in an epoxy and / or acrylic matrix. ACF can be laminated in place by curing the epoxy and / or acrylic, which essentially adheres the film to the substrate. By applying a pressure of 1 to 100 mPa to the substrate, an electrical connection is made between the metallized substrates (film and substrate dependent), thereby crushing the conductive particles between the metallizations and creating a low current carrying capacity connection. .

In some aspects, the thermal management electrical connection tapes of aspects of the present disclosure may be most closely associated with the ACF platform, but may be used as a substitute for any of the compositions and methods identified above. TMECT has high reliability in fine pitch features, requires no pressure, can be attached directly to the substrate without the use of pastes, provides low resistance connection, does not need to be refrigerated, and is expensive to manufacture It is inexpensive and in some cases eliminates the classic ACF lamination and standard performance batch process steps. TMECT can also be readily applied to standard die attach processes such as die transfer film (DTF) and wafer backside (WBS) processing.

7 is a process chart illustrating a method of using an electrical connection film for thermal management as an ACF substitute. The first step 701 includes placing the film on the first metallized substrate. The film is then laminated or pressed onto the first metallized substrate (step 702). The sample is cooled and the lamination backing is removed (step 703). After cooling, the second metallized substrate is aligned with the first metallized substrate (step 704) to form an assembly. The assembly is then left at alloy melting temperature and maintained for about 90 seconds (step 705). Finally, the assembly is cooled to room temperature (step 706).

In certain embodiments, a method of manufacturing an assembly comprising an electrical connection tape for thermal management comprises a metallization comprising a tape comprising an elastic carrier film and a composition having a solder solvent and solder powder and applied to the carrier film. Laminating between the two substrates to be connected. The laminated tapes and substrates are heated to the melting temperature of the solder powder. As the temperature rises, the carrier film to which the composition is applied melts. When mass melting of the carrier film begins, the soldering solvent is deoxidized to act as a transfer mechanism for the solder powder. When the melting temperature is reached, the deoxidized solder solvent wets only the substrate metallization and the floated solder powder is transferred to the desired metallization region by the liquid solvent. Finally cool the tape. Aspects of this method include laminating a tape between two substrates for 1 to 10 seconds at a temperature of 90 to 187 ° C. and a pressure of 0.02 to 33 psi. The melting temperature of the solder powder is 137 to 289 ° C.

Example

The electrical connection tape for thermal management containing the carrier film and the solvent composition containing a soldering solvent and solder powder was manufactured. The tape was prepared by adding 15.5% by weight of methylcyclohexane to a glass or stainless steel container with mixing capability. About 46.6 wt% ethanol was added to the solution and mixed until homogeneous. About 15.6% by weight of Versamid® 940 was then added to the solution and mixed until the solution became clear. About 9.6% by weight of Dymerex was added to the solution and mixed again until the solution became clear. About 0.2% by weight of iodobenzoic acid was then added to the solution and mixed until the solution became clear. About 1.4% by weight of dibromobutenediol was then added to the solution and mixed until the solution became clear. About 0.2% by weight of cyclohexylamine HCl was then added to the solution and mixed until the solution became clear. About 10.8% by weight adipic acid was added to the solution and mixed until the solution became clear. Finally, about 0.1% by weight of benzotriazole was added to the solution and mixed until the solution became clear.

Solder powder, SAC305 Type 3, was then added to the braze solvent solution to produce a slurry comprising about 40 wt% solder powder and 60 wt% solvent film. The composition may differ depending on the end use. The slurry was cast into tape with the carrier film, dried in a drying furnace and slit to the desired tape width. Depending on the cast thickness, the drying temperature is approximately 10-15 ° C. below the boiling point of the solvent for approximately 5-15 minutes.

It should be appreciated that the aspects of the compositions and methods discussed herein are not limited to the details of the configurations and arrangements described herein when applied. The compositions and methods can be implemented in other aspects and can be practiced or carried out in various ways. Examples of specific implementations are provided for illustrative purposes only and are not intended to be limiting. In particular, the acts, elements, and features discussed in connection with one or more aspects are not intended to be excluded from similar roles in any other aspect.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, "including", "comprising", "having", "containing", "involving" and variations thereof are listed below. And equivalents thereof as well as additional items.

Substantiating some aspects of the at least one aspect described above should be appreciated that various changes, modifications, and improvements may readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of this disclosure. Accordingly, the foregoing description and drawings are by way of example only.

Claims (18)

A thermal managing electrical connection tape,
Carrier film; And
A composition comprising solder powder and soldering flux and applied to the carrier film
Including,
Wherein the composition comprises 50 wt% to 70 wt% solder solvent and 30 wt% to 50 wt% solder powder,
Electrical connection tape for thermal management. The electrical connection tape for thermal management of Claim 1 in which the said composition contains the soldering flux in which the solder powder is arrange | positioned inside. delete delete The electrical connection tape of claim 2, wherein the composition is patterned with epoxy and / or acrylic. The electrical connection tape of claim 1, wherein the composition comprises at least one of epoxy and acrylic. The electrical connection tape of claim 1, wherein the composition comprises a “suction cup” morphology. The electrical connection tape of claim 1, wherein the composition comprises a filler that increases reliability at high pressure. The electrical connection tape of claim 8, wherein the filler comprises a glass frit. The electrical connection tape of claim 1, wherein the composition further comprises an additive for process temperature and residue evaluation. The electrical connection tape of claim 10, wherein the additive comprises at least one of Leuco, a Leuco analog, and a liquid crystal “thermochromic” dye. As a method for producing an electrical connection tape for thermal management, the method
Providing a composition comprising a braze solvent or a composition comprising a braze solvent and further comprising at least one of an epoxy and an acrylic;
Adding solder powder to the composition, wherein the composition comprises from 50 wt% to 70 wt% solder solvent and from 30 wt% to 50 wt% solder powder;
Casting the composition onto a carrier film;
Drying the carrier film in a drying furnace to form a dried tape; And
Cutting the dried tape to a desired width to form an electrical connection tape for thermal management
Including, the method. delete delete The method of claim 12, wherein the drying of the tape in a drying furnace comprises drying the tape for 5-15 minutes at a temperature of 10-15 ° C. below the boiling point of the solvent of the composition. A method of manufacturing an assembly comprising an electrical connection tape for thermal management, the method comprising
Laminating a tape comprising an elastic carrier film and a composition having a solder solvent and a solder powder and applied to the carrier film between two substrates containing metallization and to be connected, wherein the composition Comprising 50 wt% to 70 wt% soldering solvent and 30 wt% to 50 wt% solder powder;
Heating the laminated tapes and substrates to a melting temperature of the solder powder;
Melting the carrier film to which the composition is applied as the temperature rises;
When bulk melting of the carrier film starts, the soldering solvent is deoxidized to act as a transport mechanism of the solder powder;
Upon reaching the melting temperature of the solder powder, the deoxidized solder solvent only wets the metallization of the substrate, and the floated solder powder is transferred to the desired metallization region by the liquid solder solvent. ; And
Cooling the tape
Including, the method. The method of claim 16, wherein laminating the tape between the two substrates is performed for 1 to 10 seconds at a temperature of 90 to 187 ° C. and a pressure of 0.02 to 33 psi. The method of claim 16, wherein the melting temperature of the solder powder is 137 to 289 ° C. 18.

Images